System and method for generation of signatures for multimedia data elements

ABSTRACT

A method and system for generating a complex signature respective of a multimedia data element (MMDE) are provided. The method includes partitioning the MMDE into a plurality of different minimum size MMDEs; generating, for each of the different minimum MMDEs, at least one signature, wherein generation of each at least one signature is performed by a plurality of computational cores, each computational core having at least one configurable property characterizing the core, and wherein configuration of the at least one configurable property respective of each core results in statistical independence among the plurality of cores; and assembling at least a complex signature for the MMDE comprised of a plurality of the generated signatures.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/668,559 filed on Nov. 5, 2012, now U.S. Pat. No. 8,880,566, which isa continuation of U.S. patent application Ser. No. 12/538,495 filed onAug. 10, 2009, now U.S. Pat. No. 8,312,031, which is acontinuation-in-part of:

(1) U.S. patent application Ser. No. 12/084,150 having a filing date ofApr. 7, 2009, now U.S. Pat. No. 8,655,801, which is the National Stageof International Application No. PCT/IL2006/001235, filed on Oct. 26,2006, which claims foreign priority from Israeli Application No. 171577filed on Oct. 26, 2005 and Israeli Application No. 173409 filed on 29Jan. 2006;

(2) U.S. patent application Ser. No. 12/195,863, filed Aug. 21, 2008,now U.S. Pat. No. 8,326,775, which claims priority under 35 USC 119 fromIsraeli Application No. 185414, filed on Aug. 21, 2007, and which isalso a continuation-in-part of the above-referenced U.S. patentapplication Ser. No. 12/084,150; and

(3) U.S. patent application Ser. No. 12/348,888, filed Jan. 5, 2009, nowpending which is a continuation-in-part of the above-referenced U.S.patent application Ser. No. 12/084,150 and the above-referenced U.S.patent application Ser. No. 12/195,863.

All of the applications referenced above are herein incorporated byreference.

TECHNICAL FIELD

The invention relates to search of multimedia content, and morespecifically to generation of complex signatures to enable matches ofmultimedia content.

BACKGROUND

With the abundance of multimedia data made available through variousmeans in general and the Internet and world-wide web (WWW) inparticular, there is a need for effective ways of searching for, andmanagement of, such multimedia data. Searching, organizing andmanagement of multimedia data in general and video data in particularmay be challenging at best due to the difficulty of representing andcomparing the information embedded in the video content, and due to thescale of information that needs to be checked. Moreover, when it isnecessary to find a content of video by means of textual query, priorart cases revert to various metadata that textually describe the contentof the multimedia data. However, such content may be abstract andcomplex by nature and not necessarily adequately defined by the existingand/or attached metadata.

The rapidly increasing multimedia databases, accessible for examplethrough the Internet, call for the application of new methods ofrepresentation of information embedded in video content. Searching formultimedia in general and for video data in particular is challengingdue to the huge amount of information that has to be priory indexed,classified and clustered. Moreover, prior art techniques revert tomodel-based methods to define and/or describe multimedia data. However,by its very nature, the structure of such multimedia data may be tooabstract and/or complex to be adequately represented by means ofmetadata. The difficulty arises in cases where the target sought formultimedia data is not adequately defined in words, or by the respectivemetadata of the multimedia data. For example, it may be desirable tolocate a car of a particular model in a large database of video clips orsegments. In some cases the model of the car would be part of themetadata but in many cases it would not. Moreover, the car may be atangles different from the angles of a specific photograph of the carthat is available as a search item. Similarly, if a piece of music, asin a sequence of notes, is to be found, it is not necessarily the casethat in all available content the notes are known in their metadataform, or for that matter, the search pattern may just be a brief audioclip.

A system implementing a computational architecture (hereinafter “theArchitecture”) that is based on a PCT patent application publicationnumber WO 2007/049282 and published on May 3, 2007, entitled “AComputing Device, a System and a Method for Parallel Processing of DataStreams”, assigned to common assignee, is hereby incorporated byreference for all the useful information it contains. Generally, theArchitecture consists of a large ensemble of randomly, independently,generated, heterogeneous processing cores, mapping in paralleldata-segments onto a high-dimensional space and generating compactsignatures for classes of interest.

A vast amount of multimedia content exists today, whether available onthe web or on private networks, having partial or full metadata thatdescribes the content. When new content is added, it is a challenge toprovide metadata that is accurate because of the plurality of metadatathat may be potentially associated with a multimedia data element.Trying to do so manually is a tedious task and impractical in view ofthe amount of multimedia content being generated daily. Even morechallenging is the matching between different multimedia content thatrepresents the same, similar, or related concepts and/or informationfrom different perspectives. For example, an image of the WashingtonMemorial in Washington D.C., may be taken from different angles, fromdifferent distances, in different lighting conditions, and at differentpositions of the camera, so that while in one photograph the Memorial isdiagonal to the picture it is horizontal in another.

It would be therefore advantageous to provide a solution to overcome thelimitations of the prior art described hereinabove.

SUMMARY

Certain embodiments disclosed herein include a method and system forgenerating a complex signature respective of a multimedia data element(MMDE). The method comprises partitioning the MMDE into a plurality ofdifferent minimum size MMDEs; generating, for each of the differentminimum MMDEs, at least one signature, wherein generation of each atleast one signature is performed by a plurality of computational cores,each computational core having at least one configurable propertycharacterizing the core, and wherein configuration of the at least oneconfigurable property respective of each core results in statisticalindependence among the plurality of cores; and assembling at least acomplex signature for the MMDE comprised of a plurality of the generatedsignatures.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter that is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other objects, features andadvantages of the invention will be apparent from the following detaileddescription taken in conjunction with the accompanying drawings.

FIG. 1 is a block diagram depicting the basic flow of information in TheSystem in large-scale video matching.

FIG. 2 is a diagram showing the flow of patches generation, responsevector generation, and signature generation in a Large-ScaleSpeech-to-Text System implemented in accordance with certainembodiments.

FIG. 3 is a diagram illustrating the generation of complex signatures inaccordance with one embodiment.

FIG. 4 is a flowchart illustrating a method of generation of complexsignatures implemented in accordance with one embodiment.

FIG. 5 is a flowchart illustrating a method of a complex signature-basedmatching performed in accordance with one embodiment.

FIG. 6 is a block diagram of a system for generating complex signaturesconstructed in accordance with one embodiment.

DETAILED DESCRIPTION

The embodiments disclosed herein are only examples of the many possibleadvantageous uses and implementations of the innovative teachingspresented herein. In general, statements made in the specification ofthe present application do not necessarily limit any of the variousclaimed embodiments. Moreover, some statements may apply to someinventive features but not to others. In general, unless otherwiseindicated, singular elements may be in plural and vice versa with noloss of generality. In the drawings, like numerals refer to like partsthrough several views.

A method implemented according to the disclosed embodiments enables theassociation of metadata to a multimedia content based on finding matchesto similar, partially-similar and/or related multimedia content. Aninput given multimedia content is matched to at least another multimediacontent with corresponding metadata. Upon determination of a match, thecorresponding metadata is processed and then used as metadata of thegiven multimedia content. When a large number of multimedia data iscompared, a ranked list of metadata is provided. The most appropriatemetadata is associated to the input given multimedia content based onvarious criteria. The method can be implemented in any applicationswhich involve large-scale content-based clustering, recognition andclassification of multimedia data, such as, content-tracking, videofiltering, multimedia taxonomy generation, video fingerprinting,speech-to-text, audio classification, object recognition, video searchand any other application requiring content-based signatures generationand matching for large content volumes such as, web and otherlarge-scale databases.

Certain embodiments include a framework, a method, and a system, andtheir technological implementations and embodiments, for large-scalematching-based multimedia Deep Content Classification (DCC). Inaccordance with an embodiment, the system is based on the Architecturewhich is an implementation of a computational architecture described inpatent application publication number WO 2007/049282. As mentionedabove, the Architecture consists of a large ensemble of randomly,independently, generated, heterogeneous processing computational cores,mapping in parallel data-segments onto a high-dimensional space andgenerating compact signatures for classes of interest.

In accordance with the principles of the disclosed embodiments, arealization of The Architecture embedded in large-scale video matchingsystem (hereinafter “the Matching System”) for multimedia DCC isdisclosed. The Architecture receives an input stream of multimediacontent segments, injected in parallel to all computational cores. Thecomputational cores generate compact signatures of a specific contentsegment, and/or of a certain class of equivalence and interest ofcontent-segments. For large-scale volumes of data, the signatures arestored in a conventional way in a database of size N, allowing matchbetween the generated signatures of a certain content-segment and thesignatures stored in the database, and accomplishing it with a low-cost,in terms of complexity, i.e. ≦O(log N), and response time.

An embodiment of the Matching System used for the purpose of explainingthe principles of the embodiments disclosed therein is now demonstrated.Other embodiments are described in the co-pending patent applications ofwhich this patent application is a continuation-in-part of, which areincorporated herein by reference. Moreover, it is appreciated that otherembodiments will be apparent to one of ordinary skill in the art.

Characteristics and advantages of the Matching System include, but arenot limited to: the Matching System is flat and generates signatures atan extremely high throughput rate; the Matching System generates robustnatural signatures, invariant to various distortions of the signal; theMatching System is highly-scalable in high-volume signatures generation;the Matching System is highly scalable in matching against large volumesof signatures; the Matching System generates Robust Signatures for exactmatch with low cost, in terms of complexity and response time; theMatching System accuracy is scalable versus the number of computationalcores, with no degradation effect on the throughput rate of processing;the throughput of the Matching System is scalable with the number ofcomputational threads, and is scalable with the platform forcomputational cores implementation, such as FPGA, ASIC, etc.; and, theRobust Signatures produced by the Matching System are task-independent,thus the process of classification, recognition and clustering can bedone independently from the process of signatures generation, in thesuperior space of the generated signatures.

The goal of the Matching System is to effectively find matches betweenmembers of a large scale Master Database (DB) of video content-segmentsand a large scale Target DB of video content-segments. The match betweentwo video content segments should be invariant to a certain set ofstatistical distortions performed independently on two relevantcontent-segments. Moreover, the process of matching between a certaincontent-segment from the Master DB to the Target DB consisting of Nsegments, cannot be done by matching directly from the Mastercontent-segment to all N Target content-segments, for large-scale N,since the corresponding complexity of O(N), will lead to a non-practicalresponse time. Thus, the representation of content-segments by bothRobust Signatures and Signatures is crucial application-wise. TheMatching System embodies a specific realization of the Architecture forlarge scale video matching purposes.

A high-level description of the process for large scale video matchingperformed by the Matching System is depicted in FIG. 1. Video contentsegments 2 from a Master DB 6 and a Target DB 1 are processed inparallel by a large number of independent computational Cores 3 thatconstitute the Architecture. Further details on the computational Coresgeneration are provided below. The independent Cores 3 generate adatabase of Robust Signatures and Signatures 4 for Targetcontent-segments 5 and a database of Robust Signatures and Signatures 7for Master content-segments 8. An exemplary and non-limiting process ofsignature generation for an audio component is shown in detail in FIG.2. Referring back to FIG. 1, at the final step, Target Robust Signaturesand/or Signatures are effectively matched, by a matching algorithm 9, toMaster Robust Signatures and/or Signatures database to find all matchesbetween the two databases.

To demonstrate an example of signature generation process, it isassumed, merely for the sake of simplicity and without limitation on thegenerality of the invention, that the signatures are based on a singleframe, leading to certain simplification of the computational coresgeneration. The Matching System is extensible for signatures generationcapturing the dynamics in-between the frames and the information of theframe's patches.

The signatures generation process will now be described with referenceto FIG. 2. The first step in the process of signatures generation from agiven speech-segment is to break-down the speech-segment to K patches 14of random length P and random position within the speech segment 12. Thebreak-down is performed by the patch generator component 21. The valueof K and the other two parameters are determined based on optimization,considering the tradeoff between accuracy rate and the number of fastmatches required in the flow process of the System. In the next step,all the K patches are injected in parallel to all L computational Cores3 to generate K response vectors 22. The vectors 22 are fed into thesignature generator 23 to produce a Signatures and Robust Signatures 4.

In order to generate Robust Signatures, i.e., Signatures that are robustto additive noise L (where L is an integer equal to or greater than 1)computational cores are utilized in the Matching System. A frame i isinjected into all the Cores. The Cores generate two binary responsevectors: {right arrow over (S)} which is a Signature vector, and {rightarrow over (RS)} which is a Robust Signature vector.

For generation of signatures robust to additive noise, such asWhite-Gaussian-Noise, scratch, etc., but not robust to distortions, suchas crop, shift and rotation, etc., a core C_(i)={n_(i)} (1≦i≦L) mayconsist of a single leaky integrate-to-threshold unit (LTU) node or morenodes. The node n_(i) equations are:

$V_{i} = {\sum\limits_{j}{w_{ij}k_{j}}}$ n_(i) = θ_(i)(V_(i) − Th_(x));θ is a Heaviside step function; w_(ij) is a coupling node unit (CNU)between node i and image component j (for example, grayscale value of acertain pixel j); k_(j) is an image component j (for example, grayscalevalue of a certain pixel j); Th_(x) is a constant Threshold value, wherex is ‘S’ for Signature and ‘RS’ for Robust Signature; and V_(i) is aCoupling Node Value.

The Threshold values Th_(x) are set differently for Signature generationand for Robust Signature generation. For example, for a certaindistribution of V_(i) values (for the set of nodes), the thresholds forSignature (Th_(S)) and Robust Signature (Th_(RS)) are set apart, afteroptimization, according to at least one or more of the followingcriteria:

I: For: V_(i)>Th_(RS)

-   -   1−p(V>Th_(S))−1−(1−ε)^(l)<<1        i.e., given that I nodes (cores) constitute a Robust Signature        of a certain image I, the probability that not all of these I        nodes will belong to the Signature of same, but noisy image, Ĩ        is sufficiently low (according to a system's specified        accuracy).

II: p(V_(i)>Th_(RS))≈l/L

i.e., approximately l out of the total L nodes can be found to generateRobust Signature according to the above definition.

III: Both Robust Signature and Signature are generated for certain framei.

It should be understood that the creation of a signature is aunidirectional compression where the characteristics of the compresseddata are maintained but the compressed data cannot be reconstructed.Therefore, a signature can be used for the purpose of comparison toanother signature without the need of comparison of the original data.Detailed description of the signature generation process can be found inthe co-pending patent applications of which this patent application is acontinuation-in-part, and are hereby incorporated by reference.

Computational Core generation is a process of definition, selection andtuning of the Architecture parameters for a certain realization in aspecific system and application. The process is based on several designconsiderations, such as:

(a) The Cores should be designed so as to obtain maximal independence,i.e. the projection from a signal space should generate a maximalpair-wise distance between any two cores' projections into ahigh-dimensional space.

(b) The Cores should be optimally designed for the type of signals, i.e.the Cores should be maximally sensitive to the spatio-temporal structureof the injected signal, for example, and in particular, sensitive tolocal correlations in time and space. Thus, in some cases a corerepresents a dynamic system, such as state in space, phase space, edgeof chaos, etc., which is uniquely used herein to exploit their maximalcomputational power.

(c) The Cores should be optimally designed with regard to invariance toa set of signal distortions, of interest in relevant applications.

A system and method for generating complex signatures for a multimediadata element (MMDE) based on signatures of minimum size multimedia dataelements are now discussed. Accordingly, a partitioning unit partitionsthe multimedia data content into minimum size multimedia data elementsand selects a reduced set of MMDEs, based on generic low-levelcharacteristics of MMDEs. A signature generator generates signatures foreach of the selected minimum size multimedia data elements. An assemblerunit assembles a complex signature for a higher level partitionmultimedia data element by assembling respective complex signatures orsignatures of minimum size multimedia data elements of an immediatelylower partition level. Multimedia data elements include, but are notlimited to, images, graphics, video streams, video clips, audio streams,audio clips, video frames, photographs, images of signals, combinationsthereof, and portions thereof. This process generates a hologram-likerelationship within the complex-signature set of signatures, i.e., eachsignature contains some information of the complete set of multimediadata elements. While the original signature represents some localinformation about relevant multimedia data elements, the complexsignature structure enables distributed representation of theinformation of the entire set of multimedia data elements.

According to certain embodiments of the disclosed embodiments, complexsignatures, for example but without limitation, signatures as describedhereinabove, are generated for the multimedia data elements. FIG. 3shows an exemplary and non-limiting diagram illustrating the generationof such complex signatures. For the purpose of the discussion, but by nomeans of limitations or loss of generality, an image 310 is partitionedinto a plurality of portions 310-a through 310-i. An element 310-c maythen be further partitioned to elements 310-c-a, 310-c-b, . . . ,310-c-i. This of course may continue until an element 310-c-c- . . . -cis determined to be sufficiently small, for example by determining athreshold after which no additional partition takes place. It should benoted that in the description hereinabove each portion was divided intothe same number of sub-portions as the other portion, and specificallythe higher level portion; however, this is not required in order toachieve the benefits of the disclosed embodiments. In fact, the numberof sub-portions may differ from this example, and may further differ ateach stage or portion. For each of these minimum size multimedia dataelements, a signature is then generated. The signatures may be generatedbased on the principles discussed hereinabove, however, other techniquesfor generating such signatures may be used without departing from thescope of the invention.

A complex signature is a signature which is a combination of lower levelsignatures.

In the exemplary case, the signature of the multimedia element 310 istherefore the following combination: S310={S310-a, S310-b, . . .S310-i}. Each of the signatures S310-a through S310-i is also a complexsignature of lower level signatures, for example, the signature S310-cis a complex signature that is a combination of: S310-c={S310-c-a,S310-c-b, . . . S310-c-i}. As explained above, this may continue suchthat a signature S310-c-b may be a complex signature of lower levelsignatures. In one embodiment, at least the lowest level multimedia dataelements have signatures respective of at least four angularpermutations of the element, i.e., rotated by 0°, rotated by 90°,rotated by 180° and rotated by 270°. While degrees of permutations areshown herein, other permutations may be used depending on the type ofthe multimedia data element. The rationale for having such imagepermutations is to enable better matching between multimedia dataelements. The matching process is explained in detail herein below.

FIG. 4 shows an exemplary and non-limiting flowchart 400 illustratingthe method of generation of a complex signature implemented inaccordance with an embodiment. In S405, a multimedia data element isreceived, for example, from storage of The System. In S410, it ischecked if the multimedia data element is of minimum size and, if so,execution continues with S420; otherwise, execution continues with S415,where the received multimedia data element is partitioned into smallermultimedia data elements and the smaller partitions are stored in, forexample, the storage. In S420, a signature is generated for the minimumsize multimedia data element of the received multimedia data element,and the portions thereof. The signature may be generated as explainedhereinabove and/or by other signature generation means that provide asignature respective of the multimedia data element. In S430, it ischecked whether additional multimedia data elements are present and, ifso, execution continues with S420; otherwise, execution continues withS440. In S440, complex signatures are assembled for each multimedia dataelement of a particular partition level, each complex signaturecomprising a plurality of signatures of lower partition levelsignatures, as shown with respect to FIG. 3 above. In S460, it ischecked if there are multimedia data elements of a higher partitionlevel and, if not, execution continues with S480; otherwise, executioncontinues with S470, where a higher partition level is sought and thenexecution continues with S440. In S480 the generated and assembledsignatures are all stored in a storage unit, for example, the storage ofThe System.

FIG. 5 shows an exemplary and non-limiting flowchart 500 illustratingthe method for a complex signatures-based matching implemented inaccordance with an embodiment. In S510, a multimedia data element isreceived, for example, by a system that is enabled to perform matchingof signatures such as The System, and enabled for the creation ofcomplex signatures as explained hereinabove in greater detail. In S520,a process of generation of at least a complex signature takes place forthe received multimedia data element, performed, for example, inaccordance with the principles discussed with reference to FIGS. 3 and 4above. In S530, matching of the complex signature of the receivedmultimedia data element versus complex signatures stored in storage, forexample in the storage of The System, takes place. S530 comprisesmatching of all the signatures generated for the minimum size multimediadata elements. In S540, it is checked if a match score generated basedon the signatures and complex signatures is over a predefined matchingthreshold, and if so execution continues with S550; otherwise, executioncontinues with S560. In S550, a report of a match found is generated. InS560, a report of no-match found is generated. In S570, it is checkedwhether additional multimedia data elements are to be checked and, ifso, execution returns to S510; otherwise, execution terminates. Itshould be noted that the matching at the lowest level may includematching against a plurality of permutations of the minimum sizemultimedia data element, thereby increasing the chance for correctmatching between two multimedia data elements.

A complex signature may be generated by an exemplary and non-limitingsystem 600 depicted in FIG. 6. The system 600 includes a partitioningunit 610 that receives a multimedia data element and partitions themultimedia data element into small multimedia data elements. At eachlevel of partitioning, the partitioned multimedia data elements arechecked, and if the partitioned multimedia data element is above apredetermined threshold, the partitioning process continues untilreaching a level of partitioning where minimum size multimedia dataelements are generated. The signature generator 620 coupled to thepartitioning unit 610, either directly or via the storage unit 640,generates for each minimum size multimedia data element, a signature. Inone embodiment the signature is generated in accordance with signaturegeneration principles explained in more detail herein above. Theassembler unit 630 coupled to the signature generator 620 eitherdirectly or via the storage unit 640 is enabled to generate complexsignatures for each level of partitioning starting from one level abovethe level of the signatures of the minimum size multimedia dataelements. At this level the complex signature of a partitionedmultimedia data element comprises a plurality of signatures generatedfor the minimum size multimedia data elements. At levels higher thanthat level, the signature of the partitioned multimedia data element, orfor that effect, the multimedia data element received by thepartitioning unit 610, comprises a plurality of complex signaturesassembled from complex signatures of the immediately lower partitioninglevel. The complex signature and the signatures of the minimum sizemultimedia elements may be stored in the storage unit 640.

In accordance with another embodiment, the system 600 can be utilized tocompare input multimedia data elements against stored multimedia dataelements. In this embodiment, a comparison unit 650 connected to thestorage unit 640 and the assembler unit 630 is used to compare thesignatures comprising the complex signature of an input multimedia dataelement to the signatures of at least one stored multimedia dataelement. The comparison unit 650 further generates a match indicationwhen a match between the input multimedia data element and the storedmultimedia data element is found.

The principles of the invention may be implemented as hardware,firmware, software, or any combination thereof. Moreover, the softwareis preferably implemented as an application program tangibly embodied ona program storage unit or computer readable medium. The applicationprogram may be uploaded to, and executed by, a machine comprising anysuitable architecture. Preferably, the machine is implemented on acomputer platform having hardware such as one or more central processingunits (“CPUs”), a memory, and input/output interfaces. The computerplatform may also include an operating system and microinstruction code.The various processes and functions described herein may be either partof the microinstruction code or part of the application program, or anycombination thereof, which may be executed by a CPU, whether or not suchcomputer or processor is explicitly shown. In addition, various otherperipheral units may be connected to the computer platform such as anadditional data storage unit and a printing unit.

All examples and conditional language recited herein are intended forpedagogical purposes to aid the reader in understanding the principlesof the invention and the concepts contributed by the inventor tofurthering the art, and are to be construed as being without limitationto such specifically recited examples and conditions. Moreover, allstatements herein reciting principles, aspects, and embodiments of theinvention, as well as specific examples thereof, are intended toencompass both structural and functional equivalents thereof.Additionally, it is intended that such equivalents include bothcurrently known equivalents as well as equivalents developed in thefuture, i.e., any elements developed that perform the same function,regardless of structure.

What we claim is:
 1. A method for generating a complex signaturerespective of a multimedia data element (MMDE), comprising: partitioningthe MMDE into a plurality of different minimum size MMDEs; generating,for each of the different minimum size MMDEs, at least one signature,wherein generation of each of the at least one signature is performed bya plurality of computational cores, each computational core having atleast one configurable property characterizing the core, and whereinconfiguration of the at least one configurable property respective ofeach core results in statistical independence among the plurality ofcores; and assembling at least a complex signature for the MMDEcomprised of a plurality of the generated signatures.
 2. The method ofclaim 1, wherein partitioning the multimedia data element furthercomprises: partitioning each partition of a MMDE into a smaller sizeMMDE, until no further partitioning can be reached.
 3. The method ofclaim 2, wherein the plurality of minimum size MMDEs of the MMDE arepartitioned at different sizes, thereby forming different partitionlevels.
 4. The method of claim 1, wherein the signatures are generatedby a signature generator.
 5. The method of claim 1, wherein the MMDE isany one of: an image, graphics, a video stream, a video clip, an audiostream, an audio clip, a video frame, a photograph, images of signals,combinations thereof, and portions thereof.
 6. The method of claim 3,wherein the images of signals are images of any of: medical signals,geophysical signals, subsonic signals, supersonic signals,electromagnetic signals, and infrared signals.
 7. The method of claim 1,wherein each of the minimum size MMDEs is associated with signaturesrespective of at least four angular permutations of the minimum sizeMMDE.
 8. The method of claim 7, wherein the at least four angularpermutations comprise rotation of the element by 0 degrees, rotation ofthe element by 90 degrees, rotation of the element by 180 degrees, androtation of the element by 270 degrees.
 9. The method of claim 1,wherein the plurality of minimum size MMDEs of the MMDE represent allportions of the MMDE.
 10. A non-transitory computer readable mediumhaving stored thereon instructions for causing one or more processingunits to execute the method according to claim
 1. 11. A system forgenerating a complex signature respective of a multimedia data element(MMDE), comprising: a processor; and a memory, the memory containinginstructions that, when executed by the processor, configure the systemto: partition the MMDE into a plurality of different minimum size MMDEs;generate, for each of the different minimum MMDEs, at least onesignature, wherein generation of each of the at least one signature isperformed by a plurality of computational cores, each computational corehaving at least one configurable property characterizing the core, andwherein configuration of the at least one configurable propertyrespective of each core results in statistical independence among theplurality of cores; and assemble at least a complex signature for theMMDE comprised of a plurality of the generated signatures.
 12. Thesystem of claim 11, wherein the system is further configured to:partition each partition of a MMDE into a smaller size MMDE, until nofurther partitioning can be reached.
 13. The system of claim 12, whereinthe plurality of minimum size MMDEs of the MMDE are partitioned atdifferent sizes, thereby forming different partition levels.
 14. Thesystem of claim 11, wherein the generated signatures are generated by asignature generator.
 15. The system of claim 11, wherein the MMDE is anyone of: an image, graphics, a video stream, a video clip, an audiostream, an audio clip, a video frame, a photograph, images of signals,combinations thereof, and portions thereof.
 16. The system of claim 13,wherein the images of signals are images of any of: medical signals,geophysical signals, subsonic signals, supersonic signals,electromagnetic signals, and infrared signals.
 17. The system of claim11, wherein each of the minimum size MMDEs is associated with signaturesrespective of at least four angular permutations of the minimum sizeMMDE.
 18. The system of claim 17, wherein the at least four angularpermutations comprise rotation of the element by 0 degrees, rotation ofthe element by 90 degrees, rotation of the element by 180 degrees, androtation of the element by 270 degrees.
 19. The system of claim 11,wherein the plurality of minimum size MMDEs of the MMDE represent allportions of the MMDE.